How to test server-side rendering?

[fongandrew]

I'm trying to run renderToString in a test for a module meant to run on the server but getting Error: renderToString is not supported in the browser, returning undefined.

I'm using Vite with vitest and have the solid({ ssr: true }) plugin set in my Vite config. Is there some way to force it to render as if it were on a Node server? How does Solid know which environment it's in?

[atk]

Have a look at the setup of the solid-primitives project. We test both, since many of our primitives are usable in both environments.

[fongandrew]

Nice, thanks!

Quick reference for anyone else poking: https://github.com/solidjs-community/solid-primitives/blob/4af32ec3c9d97b54677ac9fa696ba11299eb2bab/configs/vitest.config.ts

[fongandrew]

Some additional notes from having to debug this six months later:

• Set environment: 'node' in the vitest config.
• Pass ssr: true to vite-plugin-solid.
• You may need to pass mode: 'ssr' in the vitest config.
• You may also need to pass --mode ssr to vitest run.

If you get Error: getContextId cannot be used under non-hydrating context, this can happen because, for whatever reason, you're mixing the server version of solid-js/web with the dev version of solid-js (in my case, solid-js/web was importing its own version of dev solid-js that ignored the conditions in my vitest config, but this went away when I applied --mode ssr via the CLI rather than just inside the vitest config.